Introducing a New Breed of Wine Yeast: Interspecific Hybridisation between a Commercial Saccharomyces cerevisiae Wine Yeast and Saccharomyces mikatae

Abstract

Interspecific hybrids are commonplace in agriculture and horticulture; bread wheat and grapefruit are but two examples. The benefits derived from interspecific hybridisation include the potential of generating advantageous transgressive phenotypes. This paper describes the generation of a new breed of wine yeast by interspecific hybridisation between a commercial Saccharomyces cerevisiae wine yeast strain and Saccharomyces mikatae, a species hitherto not associated with industrial fermentation environs. While commercially available wine yeast strains provide consistent and reliable fermentations, wines produced using single inocula are thought to lack the sensory complexity and rounded palate structure obtained from spontaneous fermentations. In contrast, interspecific yeast hybrids have the potential to deliver increased complexity to wine sensory properties and alternative wine styles through the formation of novel, and wider ranging, yeast volatile fermentation metabolite profiles, whilst maintaining the robustness of the wine yeast parent. Screening of newly generated hybrids from a cross between a S. cerevisiae wine yeast and S. mikatae (closely-related but ecologically distant members of the Saccharomyces sensu stricto clade), has identified progeny with robust fermentation properties and winemaking potential. Chemical analysis showed that, relative to the S. cerevisiae wine yeast parent, hybrids produced wines with different concentrations of volatile metabolites that are known to contribute to wine flavour and aroma, including flavour compounds associated with non-Saccharomyces species. The new S. cerevisiae x S. mikatae hybrids have the potential to produce complex wines akin to products of spontaneous fermentation while giving winemakers the safeguard of an inoculated ferment.

A Large Set of Newly Created Interspecific Saccharomyces Hybrids Increases Aromatic Diversity in Lager Beers

“…the genomes of interspecific hybrids originating from the same parents can stabilize differently, resulting in different genomic configurations, as reported in previous studies targeting interspecific hybrids (30,32,44,45). Newly developed interspecific hybrids show a broad temperature tolerance range.…”

“…Prior to phenotypic characterization, the genomes of the newly developed hybrids were therefore stabilized by growing interspecific hybrids for approximately 70 generations in industrial lager beer medium (see Materials and Methods for details). This number is shown to be sufficient to stabilize the genomes of newly formed interspecific yeast hybrids within the Saccharomyces genus (29)(30)(31)(32). Genetic stability was confirmed by genetic fingerprinting, and hybrids were considered stable when, after stabilization, both the interdelta and R3-RAPD band patterns were identical for the four biological replicates tested (see Fig.…”

“…The development of interspecific hybrids has proven to be a powerful approach to generate novel yeast variants with enhanced characteristics for wine making. Typically, an industrial strain of S. cerevisiae yeast is crossed with a wild, non-cerevisiae member of the Saccharomyces sensu stricto group, such as S. bayanus (15,(25)(26)(27), S. kudriavzevii (28,29), S. uvarum (30,31), or S. mikatae (32).…”

Large-Scale Selection and Breeding To Generate Industrial Yeasts with Superior Aroma Production

“…First, selective breeding contains the risk of yielding so-called crippled strains, i.e., strains that show improvement for the selected trait but perform worse for other industrially important phenotypes that were not selected for. This was encountered, for example, in the study of Bellon et al (30), where three out of five developed hybrids showed inferior fermentation performance. Therefore, the fermentation kinetics of the newly developed hybrids was monitored during the ale fermentations.…”

Genomic Insights into the Saccharomyces sensu stricto Complex

“…However, it is becoming increasingly evident that wine fermentations performed at lower temperature ranges are readily dominated by naturally occurring interspecific hybrids, including those formed between S. cerevisiae and either S. uvarum (González et al 2006;Le Jeune et al 2007) or S. kudriavzevii (González et al 2006;Erny et al 2012). In addition to naturally occurring interspecific hybrids, hybrids of S. cerevisiae and either S. paradoxus, S. kudriavzevii, or S. mikatae have been artificially induced for commercialization purposes (Bellon et al 2011(Bellon et al , 2013. Like the situation observed for S. pastorianus, these hybrid strains are often not complete and contain varying amounts of each parental genome (Dunn et al 2012;Erny et al 2012).…”